It is important to be able to detect counterfeit media when such media is deposited into a self-service terminal, such as when counterfeit banknotes are inserted into an automated teller machine (ATM) equipped with automated banknote validation technology. Such automated banknote validation technology typically includes high resolution line sensors. These sensors are expensive.
There is now a requirement to detect counterfeit banknotes as they are being dispensed from ATMs. This requirement has arisen because some ATM replenishers have been accessing currency cassettes to be inserted into an ATM and fraudulently substituting counterfeit banknotes for valid banknotes in those currency cassettes.
It is not practical to include banknote validation technology in every ATM because such technology is expensive and would significantly increase the transaction time for each currency dispense transaction.
It would be advantageous to have a low-cost banknote validator that does not significantly increase transaction time.